Our prior NEI multicenter Vision In Preschoolers (VIP) studies identified the most effective tests for preschool vision screening, and federal initiatives are currently underway to increase the number of preschool children receiving vision screening and eye examinations. Clinical practice guidelines for children detected with amblyopia or strabismus are clear, but no evidencebased management guidelines are available for managing the many more children detected who have moderate to large hyperopic refractive errors without amblyopia or strabismus. The requirement for accommodation in the uncorrected hyperope may result in eyestrain, headache, intermittent blur and difficulty attending at near, leading to subsequent reading and school performance problems. Several studies have linked hyperopia and reading ability, but largescale investigations have not been conducted in preschool children. Thus, the benefit of detecting children with moderate to large hyperopic refractive errors via vision screening and examining them for prescription of glasses is controversial. The proposed Vision In Preschoolers - Hyperopia In Preschoolers (VIP - HIP) cross- sectional multi-center epidemiological study will answer the following question: Do uncorrected hyperopic (e3D to <6D) 4 or 5yearold children without strabismus or amblyopia perform worse on a battery of educational tests than do comparable emmetropic children? The primary outcome measure will be performance on an assessment of literacy, the Test of Preschool Early Literacy (TOPEL). Results on literacy will be supplemented with results on assessments of attention (LeiterR sustained attention subtest), visualmotor integration (BeeryBuktenica Developmental Test of VisualMotor Integration, 5th Edition [BEERY VMI]), and behavior and development as provided by parental assessment (Connors Early Childhood [Connors EC] and the Parents' Evaluation of Development Status [PEDS]). The relation between moderate hyperopia and early educational performance will be further investigated by 1) evaluating the association of hyperopia and visual function (visual acuity at distance and near, ocular alignment, stereoacuity), and 2) evaluating accommodative response as a mechanism responsible for any relations found between hyperopia and academic performance. The proposed VIPHIP study will have substantial impact on the understanding of any effects of uncorrected hyperopia on early educational performance and visual function. The results of the study will determine the need for and relevance of a fullscale randomized clinical trial (RCT) to determine whether refractive correction in preschool improves any deficit in performance on early educational tests. The results will also have implications for vision screening policy and prescribing guidelines for glasses.